export const getmark = () => {
  const setWatermark = (str) => {
    const id = "1.23452384164.123412416";

    if (document.getElementById(id) !== null) {
      document.body.removeChild(document.getElementById(id));
    }

    //创建一个画布
    const can = document.createElement("canvas");
    //设置画布的长宽
    can.width = 150;
    can.height = 120;

    const cans = can.getContext("2d");
    //旋转角度
    cans.rotate((-15 * Math.PI) / 180);
    cans.font = "18px Vedana";
    //设置填充绘画的颜色、渐变或者模式
    cans.fillStyle = "rgba(200, 200, 200, 0.40)";
    //设置文本内容的当前对齐方式
    cans.textAlign = "left";
    //设置在绘制文本时使用的当前文本基线
    // cans.textBaseline = "Middle";
    //在画布上绘制填色的文本（输出的文本，开始绘制文本的X坐标位置，开始绘制文本的Y坐标位置）
    cans.fillText(str, can.width / 8, can.height / 2);

    const div = document.createElement("div");
    div.id = id;
    div.style.pointerEvents = "none";
    div.style.top = "30px";
    div.style.left = "0px";
    div.style.position = "fixed";
    div.style.zIndex = "100000";
    div.style.width = document.documentElement.clientWidth + "px";
    div.style.height = document.documentElement.clientHeight + "px";
    div.style.background =
      "url(" + can.toDataURL("image/png") + ") left top repeat";
    document.body.appendChild(div);
    return id;
  };

  // 该方法只允许调用一次
  const watermark = (str) => {
    let id = setWatermark(str);
    setInterval(() => {
      if (document.getElementById(id) === null) {
        id = setWatermark(str);
      }
    }, 500);
    window.onresize = () => {
      setWatermark(str);
    };
  };
  const removeWatermark = () => {
    const id = "1.23452384164.123412416";
    if (document.getElementById(id) !== null) {
      document.body.removeChild(document.getElementById(id));
    }
  }
  return { setWatermark, watermark, removeWatermark };
};